JP6661893B2 - Variable power optical system, optical device - Google Patents

Description

  The present invention relates to a variable power optical system, an optical device, and a method for manufacturing a variable power optical system.

  2. Description of the Related Art Conventionally, a variable power optical system suitable for a photographic camera, an electronic still camera, a video camera, and the like has been proposed (for example, see Patent Document 1). However, the variable power optical system as disclosed in Patent Document 1 has a problem that the optical performance is insufficient.

JP 2014-32358 A

The present invention
In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
A variable power optical system satisfying the following conditional expression is provided.
1.20 <fG1 / f1 <3.00
0.68 <(− fn) / fp <1.00
However,
fG1: focal length of the lens component closest to the object side in the first lens group f1: focal length fn of the first lens group: focal length fp of the negative lens closest to the image side in the first lens group: fp: The focal length of the positive lens closest to the image side in one lens group.
In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
The third lens group includes one lens component;
A variable power optical system satisfying the following conditional expression is provided.
1.356 ≦ fG1 / f1 <2.00
0.30 <(− f1) / f6 <0.60
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group f6: focal length of the sixth lens group
In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
A variable power optical system satisfying the following conditional expression is provided.
1.00 <fG1 / f1 <3.00
0.30 <(− f1) / f6 <0.60
0.68 <(− fn) / fp <1.00
However,
fG1: focal length of the lens component closest to the object side in the first lens group f1: focal length f6 of the first lens group f6: focal length fn of the sixth lens group: closest to the image side in the first lens group The focal length fp of the negative lens is: the focal length of the positive lens closest to the image side in the first lens group.
In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
The third lens group includes one lens component;
A variable power optical system satisfying the following conditional expression is provided.
1.00 <fG1 / f1 <2.00
0.467 ≦ (−f1) / f6 <0.60
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group f6: focal length of the sixth lens group
In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
The third lens group includes one lens component;
A variable power optical system satisfying the following conditional expression is provided.
1.00 <fG1 / f1 <3.00
0.467 ≦ (−f1) /f6≦0.544
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group f6: focal length of the sixth lens group
In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
The third lens group includes one lens component;
A variable power optical system satisfying the following conditional expression is provided.
1.60 ≦ fG1 / f1 <2.00
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group

FIG. 4 is a cross-sectional view of the zoom optical system according to Example 1 in a wide-angle end state. (A), (b) and (c) are aberration diagrams of the variable power optical system according to Example 1 at the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively, when an object at infinity is in focus. . FIG. 9 is a cross-sectional view of a zoom optical system according to a second example at the wide-angle end. (A), (b) and (c) are graphs showing various aberrations of the variable power optical system according to Example 2 upon focusing on an object at infinity in a wide-angle end state, an intermediate focal length state, and a telephoto end state. . FIG. 13 is a cross-sectional view of a zoom optical system according to a third example in a wide-angle end state. (A), (b) and (c) are aberration diagrams of the variable power optical system according to Example 3 upon focusing on an object at infinity in a wide-angle end state, an intermediate focal length state, and a telephoto end state, respectively. . FIG. 13 is a cross-sectional view of a zoom optical system according to a fourth example in a wide-angle end state. (A), (b) and (c) are aberration diagrams of the variable power optical system according to Example 4 when focused on an object at infinity in a wide-angle end state, an intermediate focal length state, and a telephoto end state, respectively. . FIG. 13 is a cross-sectional view of a zoom optical system according to a fifth example in a wide-angle end state. (A), (b) and (c) are aberration diagrams of the variable power optical system according to Example 5 when focused on an object at infinity in a wide-angle end state, an intermediate focal length state, and a telephoto end state, respectively. . FIG. 14 is a cross-sectional view of a zoom optical system according to Example 6 at the wide-angle end. (A), (b) and (c) are aberration diagrams of the variable power optical system according to Example 6 when focused on an object at infinity in a wide-angle end state, an intermediate focal length state, and a telephoto end state, respectively. . FIG. 2 is a diagram illustrating a configuration of a camera including a variable power optical system. It is a figure which shows the outline of the manufacturing method of a variable power optical system.

Hereinafter, a method of manufacturing the variable power optical system, the optical device, and the variable power optical system of the present application will be described.
The variable power optical system of the present application includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, A fourth lens group having a positive refractive power, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power. At the time of zooming, the distance between the lens groups changes, and at the time of focusing, the third lens group moves, satisfying the following conditional expression (1).
(1) 1.00 <fG1 / f1 <3.00
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group

  As described above, in the variable power optical system of the present application, the third lens group moves as a focusing lens group when focusing from an object at infinity to an object at a short distance. With this configuration, the diameter of the focusing lens group can be made relatively small. Therefore, it is possible to reduce the size and weight of the zoom optical system of the present application and to reduce the noise of the focusing operation. Further, by performing focusing with a focusing lens group having a negative refractive power, fluctuations of various aberrations such as spherical aberration and curvature of field at the time of focusing can be favorably corrected.

Conditional expression (1) defines the refractive power of the lens component closest to the object in the first lens group. In this specification, the lens component refers to a single lens or a cemented lens. By satisfying conditional expression (1), the variable power optical system of the present application can favorably correct field curvature and spherical aberration in the telephoto end state while reducing the size. When the corresponding value of the conditional expression (1) of the variable power optical system of the present application falls below the lower limit, the focal length of the lens component closest to the object side in the first lens unit decreases and the focal length of the first lens unit increases. Become. This makes it difficult to correct spherical aberration in the telephoto end state. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (1) to 1.20. On the other hand, when the corresponding value of the conditional expression (1) of the variable power optical system of the present application exceeds the upper limit, the focal length of the lens component closest to the object side in the first lens unit increases, and the focal length of the first lens unit increases. Becomes smaller. As a result, the overall length of the variable power optical system of the present application becomes large, and it becomes difficult to correct the field curvature. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (1) to 2.00.
With the above configuration, a variable power optical system having good optical performance can be realized.

It is desirable that the zoom optical system of the present application satisfies the following conditional expression (2).
(2) 0.30 <(− f1) / f6 <0.60
However,
f1: focal length of the first lens group f6: focal length of the sixth lens group

  Conditional expression (2) defines the focal length of the sixth lens group with respect to the focal length of the first lens group. By satisfying conditional expression (2), the variable power optical system of the present application can favorably correct the field curvature and the spherical aberration in the telephoto end state while reducing the size. When the corresponding value of the conditional expression (2) of the variable power optical system of the present application falls below the lower limit, the focal length of the first lens unit decreases and the focal length of the sixth lens unit increases. This makes it difficult to correct spherical aberration in the telephoto end state. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (2) to 0.40. On the other hand, when the corresponding value of the conditional expression (2) of the variable power optical system of the present application exceeds the upper limit, the focal length of the first lens unit increases and the focal length of the sixth lens unit decreases. As a result, the overall length of the variable power optical system of the present application becomes large, and it becomes difficult to correct the field curvature. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (2) to 0.52.

It is desirable that the zoom optical system of the present application satisfies the following conditional expression (3).
(3) 0.68 <(− fn) / fp <1.00
However,
fn: focal length of the negative lens closest to the image in the first lens group fp: focal length of the positive lens closest to the image in the first lens group

  Conditional expression (3) defines the focal length of the positive lens closest to the image in the first lens group with respect to the focal length of the negative lens closest to the image in the first lens group. By satisfying conditional expression (3), the variable power optical system of the present application can favorably correct lateral chromatic aberration, curvature of field, and spherical aberration in the telephoto end state while miniaturizing. When the corresponding value of the conditional expression (3) of the variable power optical system of the present application falls below the lower limit, the focal length of the negative lens closest to the image side in the first lens group decreases and the image side closest to the image side in the first lens group decreases. The focal length of the positive lens increases. This makes it difficult to correct chromatic aberration of magnification and spherical aberration in the telephoto end state. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (3) to 0.70. On the other hand, when the corresponding value of the conditional expression (3) of the variable power optical system of the present application exceeds the upper limit, the focal length of the negative lens closest to the image side in the first lens group increases, and the focal length of the negative lens in the first lens group increases. The focal length of the positive lens on the image side decreases. As a result, the overall length of the variable power optical system of the present application becomes large, and it becomes difficult to correct the field curvature. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (3) to 0.90.

  In the zoom optical system of the present application, it is desirable that the third lens group includes two or less lens components (preferably one lens component). If the third lens group, that is, the focusing lens group is composed of many lenses, it is easy to correct variations in various aberrations such as spherical aberration and field curvature during focusing. However, as the number of lenses in the third lens group increases, the overall length of the variable power optical system of the present invention increases, and it becomes difficult to reduce the size and weight. Therefore, in the variable power optical system of the present invention, the number of lenses can be reduced by configuring the third lens group with only two or less lens components as a focusing lens group as described above. In particular, it is preferable that the third lens group be constituted by a single lens because the number of lenses can be further reduced. Further, if the focusing lens group is moved to the object side when focusing from an object at infinity to an object at a short distance, fluctuations of various aberrations such as spherical aberration and field curvature at the time of focusing can be improved. Can be corrected.

  It is preferable that the variable power optical system of the present application move so that at least one lens component in the second lens group includes a component in a direction perpendicular to the optical axis. With this configuration, it is possible to perform correction of image blur caused by camera shake, vibration, or the like, that is, image stabilization. In addition, it is possible to effectively and efficiently correct a change in curvature of field during zooming.

In the zoom optical system according to the present application, it is preferable that the first lens group includes two or three lens components. With this configuration, it is possible to achieve both correction of various aberrations, particularly spherical aberration, curvature of field, and distortion, and downsizing of the variable power optical system of the present application.
In the zoom optical system of the present application, it is preferable that the first lens group has at least one positive lens. With this configuration, various aberrations, particularly, spherical aberration, curvature of field, and distortion can be favorably corrected.

  In the zoom optical system according to the present application, it is preferable that at least one of the first lens unit and the lens unit closest to the image has an aspheric surface. With this configuration, coma can be corrected.

  In the zoom optical system according to the present application, it is desirable that the lens component in the first lens group has an aspherical surface. With this configuration, the field curvature in the wide-angle end state and the spherical aberration in the telephoto end state can be corrected more efficiently. In particular, in the variable power optical system according to the present application, it is desirable that the lens surface on the image side of the lens closest to the object in the first lens group be an aspheric surface. With this configuration, distortion can be corrected, and cost and size can be reduced. The lens closest to the object in the first lens group is preferably a negative meniscus lens. With this configuration, the front lens diameter (the diameter of the lens surface closest to the object) can be reduced.

  In the zoom optical system of the present application, it is desirable that the first lens group includes a cemented lens. With this configuration, coma of each wavelength can be effectively corrected in the wide-angle end state. Further, it is desirable that the cemented lens has a meniscus shape or a biconcave shape with the convex surface facing the object side as a whole. It is desirable that the cemented lens be composed of a negative lens and a positive lens in order from the object side. It is desirable that the negative lens in the cemented lens has a meniscus shape. It is desirable that the positive lens in the cemented lens has a meniscus shape. The more the cemented lens satisfies these conditions, the less aberrations occur in the cemented lens, and the higher the mounting accuracy is not required, the less waste there is in manufacturing.

  In the zoom optical system of the present application, it is preferable that the fourth lens group includes a single lens and a cemented lens. With this configuration, spherical aberration and axial chromatic aberration can be corrected.

  It is preferable that the variable power optical system of the present application includes a plastic lens in the lens group closest to the image. Thereby, cost reduction can be achieved. In addition, the plastic lens can be provided with an aspherical surface without increasing the cost, so that the coma can be favorably corrected. In the case where the variable power optical system of the present application is an interchangeable lens, the lens closest to the image can be easily touched by the user. Therefore, it is desirable to use a glass lens having higher durability than a plastic lens.

  The optical device of the present application includes the variable power optical system having the above-described configuration. Thus, an optical device having good optical performance can be realized.

The method of manufacturing a variable power optical system according to the present application includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a negative refractive power. And a fourth lens group having a positive refractive power, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power. At the time of zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups is changed, and during focusing, the third lens group is moved. To satisfy the conditional expression (1). As a result, a variable power optical system having good optical performance can be manufactured.
(1) 1.00 <fG1 / f1 <3.00
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group

Hereinafter, a variable power optical system according to a numerical example of the present application will be described with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a sectional view of a variable power optical system according to a first embodiment of the present invention in a wide-angle end state. Arrows in FIG. 1 and FIGS. 3, 5, 7, 9 and 11 to be described later indicate movement of each lens unit during zooming from the wide-angle end state (W) to the telephoto end state (T). The trajectory is shown.

  The variable power optical system according to this example includes, in order from the object side, a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a third lens group G2 having a negative refractive power. It comprises a lens group G3, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a positive refractive power. Note that an aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side, a negative meniscus lens L12 having a convex surface facing the object side, and a positive meniscus lens L13 having a convex surface facing the object side. And a cemented lens. The image side lens surface of the negative meniscus lens L11 is aspheric.
The second lens group G2 includes a biconvex positive lens L21.
The third lens group G3 includes a negative meniscus lens L31 having a concave surface facing the object side.
The fourth lens group G4 includes, in order from the object side, a biconvex positive lens L41, a cemented lens of a biconvex positive lens L42 and a negative meniscus lens L43 having a concave surface facing the object side, an aperture stop S, Consists of
The fifth lens group G5 includes, in order from the object side, a cemented lens formed by a positive meniscus lens L51 having a concave surface facing the object side and a biconcave negative lens L52.
The sixth lens group G6 includes, in order from the object side, a positive meniscus lens L61 having a convex surface facing the object side, and a positive meniscus lens L62 having a concave surface facing the object side. The positive meniscus lens L61 is a plastic lens, and the lens surface on the image side is aspheric.

  In the variable power optical system according to this embodiment, at the time of zooming from the wide-angle end state to the telephoto end state, the air gap between the first lens group G1 and the second lens group G2, the second lens group G2 and the third lens group. G3, the air gap between the third lens group G3 and the fourth lens group G4, the air gap between the fourth lens group G4 and the fifth lens group G5, and the fifth lens group G5 and the sixth lens group G6. The first to sixth lens groups G1 to G6 move along the optical axis such that the air gap between the first lens group and the sixth lens group changes. More specifically, the second, fourth, and sixth lens groups G2, G4, and G6 move integrally during zooming. At the time of zooming, the aperture stop S moves integrally with the fourth lens group G4.

In the variable power optical system according to the present embodiment, focusing from an object at infinity to an object at a short distance is performed by moving the third lens group G3 to the object side along the optical axis.
In the variable power optical system according to this embodiment, image stabilization is performed by moving the second lens group G2 so as to include a component in a direction perpendicular to the optical axis.

Table 1 below shows values of specifications of the variable power optical system according to the present example.
In Table 1, f indicates the focal length, and Bf indicates the back focus, that is, the distance on the optical axis between the lens surface closest to the image side and the image plane.
In [surface data], the surface number is the order of the optical surfaces counted from the object side, r is the radius of curvature, d is the surface interval (the interval between the nth surface (n is an integer) and the (n + 1) th surface), and nd is The refractive index for d-line (wavelength 587.6 nm) and νd indicate Abbe number for d-line (wavelength 587.6 nm). The object surface is an object surface, the variable is a variable surface interval, and the stop S is an aperture stop S. The radius of curvature r = ∞ indicates a plane. For the aspherical surface, “*” is added to the surface number, and the value of the paraxial radius of curvature is shown in the column of the radius of curvature r.

[Aspherical surface data] shows an aspherical surface coefficient and a conical constant when the shape of the aspherical surface shown in [surface data] is represented by the following equation.
^{x = (h 2 / r)} / [1+ {1-κ (h / r) 2} 1/2] + A4h 4 + A6h 6 + A8h 8
Here, h is the height in the direction perpendicular to the optical axis, x is the distance (sag amount) along the optical axis from the tangent plane of the vertex of the aspheric surface at the height h to the aspheric surface, and κ is the conic constant , A4, A6, and A8 are aspheric coefficients, and r is a radius of curvature (paraxial radius of curvature) of the reference spherical surface. Note that “E−n” (n is an integer) indicates “× 10− ⁿ ”, and “1.23456E-07” indicates “1.23456 × 10 ⁻⁷ ”, for example. The second-order aspheric coefficient A2 is 0, and the description is omitted.

In [various data], FNO is the F number, 2ω is the angle of view (unit is “°”), Y is the image height, and TL is the total length of the variable power optical system according to the present embodiment, that is, from the first surface to the image surface. The distance on the optical axis, dn, indicates a variable distance between the n-th surface and the (n + 1) -th surface. W indicates a wide-angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state.
[Lens group data] indicates the starting surface and the focal length of each lens group.
[Conditional Expression Corresponding Value] shows the corresponding value of each conditional expression of the variable power optical system according to the present example.

Here, the unit of the focal length f, the radius of curvature r and other lengths shown in Table 1 is generally “mm”. However, the optical system is not limited to this, since the same optical performance can be obtained even if the optical system is proportionally enlarged or proportionally reduced.
Note that the reference numerals in Table 1 described above are used in the same manner in the tables of each embodiment described later.

(Table 1) First Example
[Surface data]
Surface number rd nd νd
Physical surface ∞
1 80.72 2.00 1.58913 61.22
2 18.88 0.17 1.56093 36.64
* 3 17.05 9.35 1.00000
4 240.48 1.40 1.62299 58.12
5 17.63 5.00 1.84666 23.80
6 32.74 Variable 1.00000
7 164.19 1.65 1.48749 70.31
8 -48.23 Variable 1.00000
9 -30.49 0.80 1.77250 49.62
10 -87.64 Variable 1.00000
11 46.43 3.05 1.48749 70.31
12 -31.99 0.10 1.00000
13 25.50 4.20 1.48749 70.31
14 -25.50 0.80 1.84666 23.80
15 -60.79 0.75 1.00000
16 (Aperture S) ∞ Variable 1.00000
17 -43.88 2.27 1.75520 27.57
18 -13.90 0.80 1.70154 41.02
19 38.98 Variable 1.00000
20 81.93 1.30 1.52444 56.21
* 21 91.62 1.60 1.00000
22 -179.92 2.30 1.51680 63.88
23 -21.95 Bf 1.00000
Image plane ∞
[Aspherical surface data]
Surface number κ A4 A6 A8 A10
3 0.0000 1.43618E-05 3.23919E-08 -6.25295E-11 2.95784E-13
21 0.0000 2.43150E-05 -6.35221E-09 2.24760E-10 -3.95108E-12
[Various data]
Zoom ratio 2.89
W M T
f 18.50 35.00 53.40
FNO 3.64 4.62 5.88
2ω 80.60 45.84 30.70
TL 134.86 128.74 136.72
Y 14.25 14.25 14.25
d6 33.51 11.32 3.41
d8 6.23 7.18 7.40
d10 2.96 2.00 1.78
d16 1.70 5.67 9.57
d19 9.07 5.10 1.20
Bf 43.85 59.92 75.82
[Lens group data]
Group start f
1 1 -24.58
2 7 76.67
3 9 -60.89
4 11 22.86
5 17 -31.47
6 20 46.90
[Values for conditional expressions]
(1) fG1 / f1 = 1.5
(2) (−f1) /f6=0.52
(3) (−fn) /fp=0.7813

  FIGS. 2A, 2B, and 2C show an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the variable power optical system according to the first example of the present application, respectively. FIG. 7 is a diagram illustrating various aberrations during focusing.

  In each aberration diagram, FNO indicates an F number, and Y indicates an image height. Specifically, the spherical aberration diagram shows the value of the F-number FNO corresponding to the maximum aperture, the astigmatism diagram and the distortion diagram show the maximum value of the image height Y, and the coma diagram shows the value of each image height. . In each aberration diagram, d indicates the aberration at the d-line (wavelength 587.6 nm), and g indicates the aberration at the g-line (wavelength 435.8 nm). In the astigmatism diagram, a solid line indicates a sagittal image plane, and a broken line indicates a meridional image plane. The coma aberration diagram shows the coma aberration at each image height Y. Note that the same reference numerals as in the present embodiment are used in the aberration diagrams of each embodiment described later.

  From the aberration diagrams, it can be seen that the variable power optical system according to the present example has excellent correction of various aberrations from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

(Second embodiment)
FIG. 3 is a cross-sectional view of a variable power optical system according to Example 2 of the present application in a wide-angle end state.
The variable power optical system according to this example includes, in order from the object side, a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a third lens group G2 having a negative refractive power. It comprises a lens group G3, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a positive refractive power. Note that an aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side, and a cemented lens of a biconcave negative lens L12 and a positive meniscus lens L13 having a convex surface facing the object side. Become. The image side lens surface of the negative meniscus lens L11 is aspheric.
The second lens group G2 includes a biconvex positive lens L21.
The third lens group G3 includes a negative meniscus lens L31 having a concave surface facing the object side.
The fourth lens group G4 includes, in order from the object side, a biconvex positive lens L41, and a cemented lens formed by a biconvex positive lens L42 and a negative meniscus lens L43 having a concave surface facing the object side.
The fifth lens group G5 includes, in order from the object side, an aperture stop S, and a cemented lens composed of a positive meniscus lens L51 having a concave surface facing the object side and a biconcave negative lens L52.
The sixth lens group G6 includes, in order from the object side, a negative meniscus lens L61 having a convex surface facing the object side and a positive meniscus lens L62 having a concave surface facing the object side. The negative meniscus lens L61 is a plastic lens, and the lens surface on the image side is aspheric.

  In the variable power optical system according to this embodiment, at the time of zooming from the wide-angle end state to the telephoto end state, the air gap between the first lens group G1 and the second lens group G2, the second lens group G2 and the third lens group. G3, the air gap between the third lens group G3 and the fourth lens group G4, the air gap between the fourth lens group G4 and the fifth lens group G5, and the fifth lens group G5 and the sixth lens group G6. The first to sixth lens groups G1 to G6 move along the optical axis such that the air gap between the first lens group and the sixth lens group changes. More specifically, the second, fourth, and sixth lens groups G2, G4, and G6 move integrally during zooming. The aperture stop S moves integrally with the fifth lens group G5 during zooming.

In the variable power optical system according to the present embodiment, focusing from an object at infinity to an object at a short distance is performed by moving the third lens group G3 to the object side along the optical axis.
In the variable power optical system according to this embodiment, image stabilization is performed by moving the second lens group G2 so as to include a component in a direction perpendicular to the optical axis.
Table 2 below shows values of the specifications of the variable power optical system according to the present example.

(Table 2) Second embodiment
[Surface data]
Surface number rd nd νd
Physical surface ∞
1 58.61 1.30 1.51680 63.88
2 18.70 0.15 1.56093 36.64
* 3 16.70 12.36 1.00000
4 -539.76 1.20 1.63854 55.34
5 21.43 5.00 1.84666 23.78
6 43.93 Variable 1.00000
7 76.20 1.70 1.48749 70.31
8 -74.28 Variable 1.00000
9 -33.55 0.79 1.77250 49.62
10 -126.41 Variable 1.00000
11 49.80 3.33 1.48749 70.31
12 -30.52 0.10 1.00000
13 23.62 3.51 1.48749 70.31
14 -29.49 0.80 1.84666 23.80
15 -75.25 Variable 1.00000
16 (Aperture S) ∞ 1.50 1.00000
17 -51.95 2.42 1.75520 27.57
18 -15.57 0.90 1.70154 41.02
19 45.98 Variable 1.00000
20 96.48 1.37 1.52444 56.21
* 21 88.50 1.50 1.00000
22 -58.97 2.38 1.51680 63.88
23 -21.70 Bf 1.00000
Image plane ∞
[Aspherical surface data]
Surface number κ A4 A6 A8 A10
3 0.0000 1.72915E-05 4.86464E-08 -1.24525E-10 4.71298E-13
21 0.0000 3.10082E-05 1.62502E-09 -1.14900E-10 1.87133E-13
[Various data]
Zoom ratio 2.89
W M T
f 18.50 35.00 53.40
FNO 3.64 4.70 5.84
2ω 80.61 45.83 30.72
TL 135.29 129.95 136.93
Y 14.25 14.25 14.25
d6 35.50 13.00 3.00
d8 6.10 9.67 10.06
d10 5.11 1.55 1.15
d15 0.95 3.60 6.50
d19 6.85 4.20 1.30
Bf 40.47 57.64 74.61
[Lens group data]
Group start f
1 1 -27.41
2 7 77.45
3 9 -59.34
4 11 22.44
5 17 -37.49
6 20 67.25
[Values for conditional expressions]
(1) fG1 / f1 = 1.6
(2) (−f1) /f6=0.41
(3) (−fn) /fp=0.7192

  FIGS. 4A, 4B, and 4C respectively show an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom optical system according to the second example of the present application. FIG. 7 is a diagram illustrating various aberrations during focusing.

  From the aberration diagrams, it can be seen that the variable power optical system according to the present example has excellent correction of various aberrations from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

(Third embodiment)
FIG. 5 is a cross-sectional view of a zoom optical system according to Example 3 of the present application in a wide-angle end state.
The variable power optical system according to this example includes, in order from the object side, a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a third lens group G2 having a negative refractive power. It comprises a lens group G3, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a positive refractive power. Note that an aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side, a negative meniscus lens L12 having a convex surface facing the object side, and a positive meniscus lens L13 having a convex surface facing the object side. And a cemented lens. The image side lens surface of the negative meniscus lens L11 is aspheric.
The second lens group G2 includes a positive meniscus lens L21 having a concave surface facing the object side.
The third lens group G3 includes a negative meniscus lens L31 having a concave surface facing the object side.
The fourth lens group G4 includes, in order from the object side, a biconvex positive lens L41, a cemented lens of a biconvex positive lens L42 and a negative meniscus lens L43 having a concave surface facing the object side, an aperture stop S, Consists of
The fifth lens group G5 includes, in order from the object side, a cemented lens formed by a positive meniscus lens L51 having a concave surface facing the object side and a biconcave negative lens L52.
The sixth lens group G6 includes, in order from the object side, a negative meniscus lens L61 having a convex surface facing the object side and a positive meniscus lens L62 having a concave surface facing the object side. The negative meniscus lens L61 is a plastic lens, and the lens surface on the image side is aspheric.

  In the variable power optical system according to this embodiment, at the time of zooming from the wide-angle end state to the telephoto end state, the air gap between the first lens group G1 and the second lens group G2, the second lens group G2 and the third lens group. G3, the air gap between the third lens group G3 and the fourth lens group G4, the air gap between the fourth lens group G4 and the fifth lens group G5, and the fifth lens group G5 and the sixth lens group G6. The first to sixth lens groups G1 to G6 move along the optical axis such that the air gap between the first lens group and the sixth lens group changes. At the time of zooming, the aperture stop S moves integrally with the fourth lens group G4.

In the variable power optical system according to the present embodiment, focusing from an object at infinity to an object at a short distance is performed by moving the third lens group G3 to the object side along the optical axis.
In the variable power optical system according to this embodiment, image stabilization is performed by moving the second lens group G2 so as to include a component in a direction perpendicular to the optical axis.
Table 3 below shows values of specifications of the variable power optical system according to the present example.

(Table 3) Third embodiment
[Surface data]
Surface number rd nd νd
Physical surface ∞
1 79.69 2.00 1.58913 61.22
2 20.75 0.17 1.56093 36.64
* 3 19.00 9.65 1.00000
4 416.05 1.40 1.60311 60.69
5 17.31 5.19 1.84666 23.80
6 28.95 Variable 1.00000
7 -396.42 1.63 1.48749 70.31
8 -34.31 Variable 1.00000
9 -24.55 0.80 1.77250 49.62
10 -67.66 Variable 1.00000
11 53.51 2.86 1.60311 60.69
12 -36.03 0.10 1.00000
13 26.08 4.26 1.48749 70.31
14 -23.14 0.80 1.84666 23.80
15 -52.27 0.75 1.00000
16 (Aperture S) ∞ Variable 1.00000
17 -45.51 2.28 1.84666 23.80
18 -14.24 0.80 1.74950 35.25
19 41.61 Variable 1.00000
20 100.00 1.30 1.52444 56.21
* 21 97.03 1.55 1.00000
22 -306.68 2.44 1.48749 70.31
23 -21.59 Bf 1.00000
Image plane ∞
[Aspherical surface data]
Surface number κ A4 A6 A8 A10
3 0.0000 9.56997E-06 2.46213E-08 -3.67381E-11 1.68777E-13
21 0.0000 2.66274E-05 2.95181E-08 -8.46694E-11 -4.35134E-12
[Various data]
Zoom ratio 2.89
W M T
f 18.50 35.00 53.40
FNO 3.64 4.60 5.88
2ω 80.59 45.80 30.69
TL 134.92 128.32 136.32
Y 14.25 14.25 14.25
d6 33.91 11.51 3.67
d8 5.54 6.25 6.51
d10 2.36 1.94 1.78
d16 1.70 5.75 9.71
d19 9.61 5.26 1.20
Bf 43.82 59.63 75.47
[Lens group data]
Group start f
1 1 -24.72
2 7 76.93
3 9 -50.29
4 11 21.61
5 17 -33.17
6 20 48.02
[Values for conditional expressions]
(1) fG1 / f1 = 1.7
(2) (−f1) /f6=0.51
(3) (−fn) /fp=0.7099

  FIGS. 6A, 6B, and 6C respectively show an object at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom optical system according to Example 3 of the present application. FIG. 7 is a diagram illustrating various aberrations during focusing.

  From the aberration diagrams, it can be seen that the variable power optical system according to the present example has excellent correction of various aberrations from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

(Fourth embodiment)
FIG. 7 is a cross-sectional view of a variable power optical system according to Example 4 of the present application in a wide-angle end state.
The variable power optical system according to this example includes, in order from the object side, a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a third lens group G2 having a negative refractive power. It comprises a lens group G3, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a positive refractive power. Note that an aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side, and a cemented lens of a biconcave negative lens L12 and a positive meniscus lens L13 having a convex surface facing the object side. Become. The image side lens surface of the negative meniscus lens L11 is aspheric.
The second lens group G2 includes a positive meniscus lens L21 having a concave surface facing the object side.
The third lens group G3 includes a negative meniscus lens L31 having a concave surface facing the object side.
The fourth lens group G4 includes, in order from the object side, a biconvex positive lens L41, a cemented lens of a biconvex positive lens L42 and a negative meniscus lens L43 having a concave surface facing the object side, an aperture stop S, Consists of
The fifth lens group G5 includes, in order from the object side, a cemented lens formed by a positive meniscus lens L51 having a concave surface facing the object side and a biconcave negative lens L52.
The sixth lens group G6 includes, in order from the object side, a negative meniscus lens L61 having a convex surface facing the object side and a positive meniscus lens L62 having a concave surface facing the object side. The negative meniscus lens L61 is a plastic lens, and the lens surface on the image side is aspheric.

  In the variable power optical system according to this embodiment, at the time of zooming from the wide-angle end state to the telephoto end state, the air gap between the first lens group G1 and the second lens group G2, the second lens group G2 and the third lens group. G3, the air gap between the third lens group G3 and the fourth lens group G4, the air gap between the fourth lens group G4 and the fifth lens group G5, and the fifth lens group G5 and the sixth lens group G6. The first to sixth lens groups G1 to G6 move along the optical axis such that the air gap between the first lens group and the sixth lens group changes. At the time of zooming, the aperture stop S moves integrally with the fourth lens group G4.

In the variable power optical system according to the present embodiment, focusing from an object at infinity to an object at a short distance is performed by moving the third lens group G3 to the object side along the optical axis.
In the variable power optical system according to this embodiment, image stabilization is performed by moving the second lens group G2 so as to include a component in a direction perpendicular to the optical axis.
Table 4 below shows values of specifications of the variable power optical system according to the present example.

(Table 4) Fourth embodiment
[Surface data]
Surface number rd nd νd
Physical surface ∞
1 56.24 2.00 1.69680 55.52
2 20.35 0.17 1.56093 36.64
* 3 18.69 9.97 1.00000
4 -2982.47 1.40 1.60 300 65.44
5 18.31 5.00 1.84666 23.80
6 32.46 Variable 1.00000
7 -620.57 1.63 1.48749 70.31
8 -35.68 Variable 1.00000
9 -25.12 0.80 1.77250 49.62
10 -71.26 Variable 1.00000
11 54.96 2.89 1.60311 60.69
12 -35.02 0.10 1.00000
13 25.68 4.30 1.48749 70.31
14 -23.22 0.80 1.84666 23.80
15 -52.65 0.75 1.00000
16 (Aperture S) ∞ Variable 1.00000
17 -45.18 2.27 1.84666 23.80
18 -14.36 0.80 1.74950 35.25
19 41.64 Variable 1.00000
20 100.05 1.30 1.52444 56.21
* 21 80.01 1.54 1.00000
22 -416.31 2.37 1.48749 70.31
23 -21.63 Bf 1.00000
Image plane ∞
[Aspherical surface data]
Surface number κ A4 A6 A8 A10
3 0.0000 1.09721E-05 2.63109E-08 -3.94901E-11 1.79030E-13
21 0.0000 2.64794E-05 1.52619E-08 5.85840E-11 -4.79996E-12
[Various data]
Zoom ratio 2.89
W M T
f 18.50 35.00 53.40
FNO 3.63 4.60 5.88
2ω 80.59 45.83 30.72
TL 134.92 128.32 136.32
Y 14.25 14.25 14.25
d6 34.40 11.79 3.56
d8 5.58 6.27 6.52
d10 2.36 1.87 1.82
d15 1.70 5.48 9.09
d19 8.98 5.00 1.20
Bf 43.82 59.84 76.07
[Lens group data]
Group start f
1 1 -24.76
2 7 77.60
3 9 -50.59
4 11 21.42
5 17 -32.97
6 20 49.70
[Values for conditional expressions]
(1) fG1 / f1 = 1.7
(2) (−f1) /f6=0.50
(3) (−fn) /fp=0.7067

  FIGS. 8A, 8B, and 8C respectively show an object at infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom optical system according to Example 4 of the present application. FIG. 7 is a diagram illustrating various aberrations during focusing.

  From the aberration diagrams, it can be seen that the variable power optical system according to the present example has excellent correction of various aberrations from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

(Fifth embodiment)
FIG. 9 is a cross-sectional view of a zoom optical system according to Example 5 of the present application in a wide-angle end state.
The variable power optical system according to this example includes, in order from the object side, a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a third lens group G2 having a negative refractive power. It comprises a lens group G3, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a positive refractive power. Note that an aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side, a negative meniscus lens L12 having a convex surface facing the object side, and a positive meniscus lens L13 having a convex surface facing the object side. Consists of The image side lens surface of the negative meniscus lens L11 is aspheric.
The second lens group G2 includes a positive meniscus lens L21 having a concave surface facing the object side.
The third lens group G3 includes a negative meniscus lens L31 having a concave surface facing the object side.
The fourth lens group G4 includes, in order from the object side, a biconvex positive lens L41, a cemented lens of a biconvex positive lens L42 and a negative meniscus lens L43 having a concave surface facing the object side, an aperture stop S, Consists of
The fifth lens group G5 includes, in order from the object side, a cemented lens formed by a positive meniscus lens L51 having a concave surface facing the object side and a biconcave negative lens L52.
The sixth lens group G6 includes, in order from the object, a positive lens L61 and a positive meniscus lens L62 having a concave surface facing the object. The positive lens L61 is a plastic lens, and the lens surface on the image side is aspheric.

  In the variable power optical system according to this embodiment, at the time of zooming from the wide-angle end state to the telephoto end state, the air gap between the first lens group G1 and the second lens group G2, the second lens group G2 and the third lens group. G3, the air gap between the third lens group G3 and the fourth lens group G4, the air gap between the fourth lens group G4 and the fifth lens group G5, and the fifth lens group G5 and the sixth lens group G6. The first to sixth lens groups G1 to G6 move along the optical axis such that the air gap between the first lens group and the sixth lens group changes. At the time of zooming, the aperture stop S moves integrally with the fourth lens group G4.

In the variable power optical system according to the present embodiment, focusing from an object at infinity to an object at a short distance is performed by moving the third lens group G3 to the object side along the optical axis.
In the variable power optical system according to this embodiment, image stabilization is performed by moving the second lens group G2 so as to include a component in a direction perpendicular to the optical axis.
Table 5 below shows values of specifications of the variable power optical system according to the present example.

(Table 5) Fifth embodiment
[Surface data]
Surface number rd nd νd
Physical surface ∞
1 159.78 2.00 1.58913 61.22
2 21.25 0.17 1.56093 36.64
* 3 18.31 8.37 1.00000
4 80.67 1.40 1.62299 58.12
5 17.61 0.45 1.00000
6 18.34 5.10 1.84666 23.80
7 31.58 Variable 1.00000
8 -1394.74 1.62 1.48749 70.31
9 -36.39 Variable 1.00000
10 -23.60 0.80 1.77250 49.62
11 -66.38 Variable 1.00000
12 52.65 2.85 1.60311 60.69
13 -38.60 0.10 1.00000
14 32.14 4.27 1.48749 70.31
15 -22.40 0.80 1.84666 23.80
16 -43.56 0.75 1.00000
17 (Aperture S) 可 変 Variable 1.00000
18 -58.32 2.38 1.80518 25.45
19 -14.79 0.80 1.74950 35.25
20 51.07 Variable 1.00000
21 100.00 1.30 1.52444 56.21
* 22 100.00 1.60 1.00000
23 -157.66 2.20 1.48749 70.31
24 -23.26 Bf 1.00000
Image plane ∞
[Aspherical surface data]
Surface number κ A4 A6 A8 A10
3 0.0000 7.24382E-06 8.06638E-13 5.77349E-11 -2.00588E-13
22 0.0000 2.45605E-05 6.34787E-08 -1.05676E-09 5.28455E-12
[Various data]
Zoom ratio 2.89
W M T
f 18.50 35.00 53.40
FNO 3.63 4.60 5.88
2ω 80.59 45.92 30.76
TL 134.92 128.32 136.32
Y 14.25 14.25 14.25
d7 34.09 11.78 3.56
d9 5.92 6.31 6.55
d11 3.79 2.29 1.78
d17 1.70 6.12 10.47
d20 8.58 5.27 1.20
Bf 43.85 59.57 75.79
[Lens group data]
Group start f
1 1 -26.08
2 8 76.62
3 10 -47.81
4 12 22.59
5 18 -40.02
6 21 55.85
[Values for conditional expressions]
(1) fG1 / f1 = 1.4
(2) (-f1) / f6 = 0.4670
(3) (-fn) / fp = 0.831

  FIGS. 10A, 10B, and 10C respectively show an infinity object in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom optical system according to Example 5 of the present application. FIG. 7 is a diagram illustrating various aberrations during focusing.

  From the aberration diagrams, it can be seen that the variable power optical system according to the present example has excellent correction of various aberrations from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

(Sixth embodiment)
FIG. 11 is a sectional view of a zoom optical system according to Example 6 of the present application in a wide-angle end state.
The variable power optical system according to this example includes, in order from the object side, a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a third lens group G2 having a negative refractive power. It comprises a lens group G3, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a positive refractive power. Note that an aperture stop S is disposed between the fourth lens group G4 and the fifth lens group G5.

The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side, a negative meniscus lens L12 having a convex surface facing the object side, and a positive meniscus lens L13 having a convex surface facing the object side. Consists of The image side lens surface of the negative meniscus lens L11 is aspheric.
The second lens group G2 includes a positive meniscus lens L21 having a concave surface facing the object side.
The third lens group G3 includes a negative meniscus lens L31 having a concave surface facing the object side.
The fourth lens group G4 includes, in order from the object side, a biconvex positive lens L41, a cemented lens of a biconvex positive lens L42 and a negative meniscus lens L43 having a concave surface facing the object side, an aperture stop S, Consists of
The fifth lens group G5 includes, in order from the object side, a cemented lens composed of a biconcave negative lens L51 and a positive meniscus lens L52 having a convex surface facing the object side.
The sixth lens group G6 includes, in order from the object side, a positive meniscus lens L61 having a convex surface facing the object side, and a positive meniscus lens L62 having a concave surface facing the object side. The positive meniscus lens L61 is a plastic lens, and the lens surface on the image side is aspheric.

  In the variable power optical system according to this embodiment, at the time of zooming from the wide-angle end state to the telephoto end state, the air gap between the first lens group G1 and the second lens group G2, the second lens group G2 and the third lens group. G3, the air gap between the third lens group G3 and the fourth lens group G4, the air gap between the fourth lens group G4 and the fifth lens group G5, and the fifth lens group G5 and the sixth lens group G6. The first to sixth lens groups G1 to G6 move along the optical axis such that the air gap between the first lens group and the sixth lens group changes. At the time of zooming, the aperture stop S moves integrally with the fourth lens group G4.

In the variable power optical system according to the present embodiment, focusing from an object at infinity to an object at a short distance is performed by moving the third lens group G3 to the object side along the optical axis.
In the variable power optical system according to this embodiment, image stabilization is performed by moving the second lens group G2 so as to include a component in a direction perpendicular to the optical axis.
Table 6 below lists the values of the specifications of the variable power optical system according to the present example.

(Table 6) Sixth embodiment
[Surface data]
Surface number rd nd νd
Physical surface ∞
1 157.01 2.00 1.58913 61.22
2 21.49 0.17 1.56093 36.64
* 3 18.52 8.66 1.00000
4 106.51 1.40 1.62299 58.12
5 18.80 0.53 1.00000
6 19.87 4.91 1.84666 23.80
7 36.41 Variable 1.00000
8 -11963.03 1.64 1.48749 70.31
9 -37.51 Variable 1.00000
10 -26.10 0.80 1.77250 49.62
11 -85.54 Variable 1.00000
12 52.74 2.90 1.60311 60.69
13 -36.25 0.10 1.00000
14 27.94 4.00 1.48749 70.31
15 -28.59 0.80 1.84666 23.80
16 -77.61 0.81 1.00000
17 (Aperture S) 可 変 Variable 1.00000
18 -78.97 0.80 1.74950 35.25
19 13.08 2.35 1.80518 25.45
20 37.73 Variable 1.00000
21 80.00 1.30 1.52444 56.21
* 22 96.77 1.61 1.00000
23 -143.56 2.26 1.48749 70.31
24 -21.47 Bf 1.00000
Image plane ∞
[Aspherical surface data]
Surface number κ A4 A6 A8 A10
3 0.0000 6.82101E-06 5.13428E-09 1.12442E-11 -1.05343E-13
22 0.0000 2.46633E-05 1.73045E-07 -3.90358E-09 3.12442E-11
[Various data]
Zoom ratio 2.89
W M T
f 18.50 35.00 53.40
FNO 3.61 4.60 5.88
2ω 80.60 45.96 30.78
TL 134.92 128.32 136.72
Y 14.25 14.25 14.25
d7 34.87 11.92 3.45
d9 5.77 6.47 6.64
d11 3.33 2.07 1.82
d17 1.70 5.70 9.50
d20 8.37 4.94 1.21
Bf 43.85 60.19 77.07
[Lens group data]
Group start f
1 1 -26.64
2 8 77.18
3 10 -48.90
4 12 23.15
5 18 -37.32
6 21 48.99
[Values for conditional expressions]
(1) fG1 / f1 = 1.356
(2) (−f1) /f6=0.544
(3) (-fn) / fp = 0.811

  FIGS. 12A, 12B, and 12C respectively show an infinite distance object, a middle focal length state, and a telephoto end state of the variable power optical system according to Example 6 of the present application. FIG. 7 is a diagram illustrating various aberrations during focusing.

  From the aberration diagrams, it can be seen that the variable power optical system according to the present example has excellent correction of various aberrations from the wide-angle end state to the telephoto end state, and has excellent imaging performance.

  According to each of the above embodiments, it is possible to realize a variable power optical system which is small and lightweight, suppresses fluctuation of aberration at the time of variable power, and has excellent optical performance.

  Each of the above embodiments is a specific example of the present invention, and the present invention is not limited thereto. The following contents can be appropriately adopted without impairing the optical performance of the variable power optical system of the present application.

  The numerical examples of the variable power optical system of the present application are shown as having six groups, but the present invention is not limited to this, and it is also possible to configure a variable power optical system having another group structure (for example, seven groups). . Specifically, a configuration in which a lens or a lens group is added to the most object side or the most image side of the variable power optical system of each of the above embodiments may be used. Further, the lens group closest to the image side of the variable power optical system in each of the above embodiments may be divided into two, and the distance between them may be changed at the time of variable power.

Each of the variable power optical systems of the above embodiments has a configuration in which each lens group moves along the optical axis when changing the power from the wide-angle end state to the telephoto end state. However, in the variable power optical system of each of the above embodiments, the position of at least one lens group, for example, the lens group closest to the image may be fixed. In addition, it is preferable that the movement trajectory of the first lens unit during zooming from the wide-angle end state to the telephoto end state has a U-turn shape that moves to the image side and then moves to the object side. Further, by making the movement trajectories of the non-adjacent lens units at the time of zooming the same, a plurality of lens units can be linked and moved integrally. By linking and integrally moving a plurality of lens groups, the lens group holding structure in the lens barrel can be simplified, which contributes to downsizing.
Further, the variable power optical system of each of the above embodiments may be in a reduced cylinder state in which the distance between lenses is further reduced. The variable power optical system of each of the above embodiments can improve portability by adopting a reduced cylinder state. In the variable power optical system of each of the above-described embodiments, it is preferable that the distance between the first lens group and the second lens group having the largest distance between the lens groups is reduced to change the state to the reduced cylinder state.

  In addition, in order to focus from an object at infinity to an object at a short distance, the variable power optical system according to each of the above-described embodiments includes a part of a lens group, one entire lens group, or a plurality of lens groups. It may be configured to be moved as a group in the optical axis direction. In particular, in the variable power optical system of each of the above embodiments, it is desirable that the third lens group be a focusing lens group. Such a focusing lens group can also be applied to autofocus, and is also suitable for driving by a motor for autofocus, for example, an ultrasonic motor.

  Further, in the variable power optical system of each of the above embodiments, the whole or a part of any of the lens groups is moved so as to include a component in a direction perpendicular to the optical axis as an image stabilizing lens group, or By performing rotational movement (oscillation) in the in-plane direction including the above, it is also possible to adopt a configuration in which vibration is prevented. In particular, in the variable power optical system of each of the above-described embodiments, it is preferable that the second lens group is a vibration-proof lens group. In the variable power optical system of each of the above embodiments, the fifth lens group may be a vibration-proof lens group.

  Further, the lens surface of the lens constituting the variable power optical system in each of the above embodiments may be a spherical surface, a flat surface, or an aspheric surface. When the lens surface is a spherical surface or a flat surface, lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to errors in lens processing and assembly adjustment can be prevented. Further, even when the image plane is displaced, it is preferable because the deteriorating performance is small. When the lens surface is an aspherical surface, any of an aspherical surface by grinding, a glass molded aspherical surface obtained by molding glass into an aspherical shape with a mold, or a composite aspherical surface formed by forming a resin provided on the glass surface into an aspherical shape is used. Good. The lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

  In the variable magnification optical system of each of the above embodiments, the aperture stop is preferably disposed between the fourth lens group and the fifth lens group, and the role is substituted by a lens frame without providing a member as the aperture stop. It may be configured.

  Further, an antireflection film having a high transmittance in a wide wavelength range may be provided on the lens surface of the lens constituting the variable power optical system in each of the above embodiments. Thereby, flare and ghost can be reduced, and high optical performance with high contrast can be achieved. In particular, in the variable power optical system of each of the above embodiments, it is preferable that an antireflection film is formed on the object side lens surface of the lens included in the lens group closest to the image.

Next, a camera provided with the variable power optical system of the present application will be described with reference to FIG.
FIG. 13 is a diagram showing a configuration of a camera provided with the variable power optical system of the present application.
The camera 1 is a digital single-lens reflex camera of an interchangeable lens type provided with the variable power optical system according to the first embodiment as the taking lens 2.
In the present camera 1, light from a not-shown object, which is a subject, is condensed by a photographing lens 2 and is imaged on a focusing screen 4 via a quick return mirror 3. The light focused on the reticle 4 is reflected a plurality of times in the pentaprism 5 and guided to the eyepiece 6. This allows the photographer to observe the subject image as an erect image via the eyepiece 6.
When the release button (not shown) is pressed by the photographer, the quick return mirror 3 is retracted out of the optical path, and light from a subject (not shown) reaches the image sensor 7. As a result, light from the subject is picked up by the image pickup device 7 and recorded in a memory (not shown) as a subject image. In this way, the photographer can photograph the subject with the camera 1.

  Here, the variable power optical system according to the first embodiment mounted on the camera 1 as the photographing lens 2 has a small size and excellent optical performance as described above. That is, the present camera 1 can realize miniaturization and excellent optical performance. It should be noted that the same effect as the camera 1 can be obtained even when a camera equipped with the variable power optical system according to the second to sixth embodiments as the taking lens 2 is configured. Further, even when the variable power optical system according to each of the above embodiments is mounted on a camera having no quick return mirror 3, the same effects as those of the camera 1 can be obtained.

Finally, an outline of a method of manufacturing the variable power optical system of the present application will be described with reference to FIG.
FIG. 14 is a diagram schematically illustrating a method of manufacturing a variable power optical system according to the present application.
The method of manufacturing a variable power optical system according to the present invention shown in FIG. 14 includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a negative lens power. Manufacturing method of a variable power optical system including a third lens group, a fourth lens group having a positive refractive power, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power. And includes the following steps S1 to S3.
Step S1: First to sixth lens groups are prepared, and each lens group is arranged in the lens barrel in order from the object side. Then, by providing a known moving mechanism in the lens barrel, the distance between the lens groups is changed at the time of zooming from the wide-angle end state to the telephoto end state.
Step S2: By providing a known moving mechanism in the lens barrel, the third lens group is moved at the time of focusing from an object at infinity to an object at a short distance.
Step S3: The variable power optical system satisfies the following conditional expression (1).
(1) 1.00 <fG1 / f1 <3.00
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group

  According to such a method of manufacturing a variable power optical system of the present application, it is possible to manufacture a variable power optical system that is small and has good optical performance.

G1: first lens group, G2: second lens group, G3: third lens group, G4: fourth lens group, G5: fifth lens group, G6: sixth lens group, G7: seventh lens group, S : Aperture stop, W: wide angle end, T: telephoto end

Claims (11)

In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
A variable power optical system satisfying the following conditional expression.
1.20 <fG1 / f1 <3.00
0.68 <(− fn) / fp <1.00
However,
fG1: focal length of the lens component closest to the object side in the first lens group f1: focal length fn of the first lens group: focal length fp of the negative lens closest to the image side in the first lens group: fp: Focal length of the most image-side positive lens in one lens group In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
The third lens group includes one lens component;
A variable power optical system satisfying the following conditional expression.
1.356 ≦ fG1 / f1 <2.00
0.30 <(− f1) / f6 <0.60
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group f6: focal length of the sixth lens group In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
A variable power optical system satisfying the following conditional expression.
1.00 <fG1 / f1 <3.00
0.30 <(− f1) / f6 <0.60
0.68 <(− fn) / fp <1.00
However,
fG1: focal length of the lens component closest to the object side in the first lens group f1: focal length f6 of the first lens group f6: focal length fn of the sixth lens group: closest to the image side in the first lens group Focal length fp of the negative lens: focal length of the most image-side positive lens in the first lens group In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
The third lens group includes one lens component;
A variable power optical system satisfying the following conditional expression.
1.00 <fG1 / f1 <2.00
0.467 ≦ (−f1) / f6 <0.60
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group f6: focal length of the sixth lens group In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
The third lens group includes one lens component;
A variable power optical system satisfying the following conditional expression.
1.00 <fG1 / f1 <3.00
0.467 ≦ (−f1) /f6≦0.544
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group f6: focal length of the sixth lens group In order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens having a positive refractive power A group, a fifth lens group having a negative refractive power, and a sixth lens group having a positive refractive power, the lens group substantially includes six lens groups ;
During zooming between the wide-angle end state and the telephoto end state, the distance between the lens groups changes,
At the time of focusing, the third lens group moves,
The third lens group includes one lens component;
A variable power optical system satisfying the following conditional expression.
1.60 ≦ fG1 / f1 <2.00
However,
fG1: focal length of the lens component closest to the object in the first lens group f1: focal length of the first lens group The variable power optical system according to claim 1 or 6, wherein the following conditional expression is satisfied.
0.30 <(− f1) / f6 <0.60
However,
f1: focal length of the first lens group f6: focal length of the sixth lens group The variable power optical system according to claim 2, wherein the following conditional expression is satisfied.
0.68 <(− fn) / fp <1.00
However,
fn: focal length of the negative lens closest to the image in the first lens group fp: focal length of the positive lens closest to the image in the first lens group   4. The variable power optical system according to claim 1, wherein the third lens group includes one lens component.   The variable power optical system according to claim 1, wherein at least one lens component in the second lens group moves so as to include a component in a direction perpendicular to an optical axis.   An optical device comprising the variable power optical system according to claim 1.

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